Photographic images or images as typified by a poster have been prepared by a conventional silver salt photographic system or printing system such as gravure printing but recently are also prepared by an ink jet printer or an electrophotographic image forming apparatus.
In the field of an image forming technology of an electrophotographic system for copiers or printers, for instance, reproduction of minute dot images at a level of 1200 dpi [in which “dpi” refers to the number of dots per inch (2.54 cm)] has become feasible along with development of technologies, such as digitization of an exposure system or reduction of toner particle sizes. Further, there has been developed a technology in which toner images are formed on plural photoreceptor drums, the formed toner images are primarily transferred to an intermediate transfer material to be superimposed and the toner images transferred onto the intermediate transfer material are secondarily transferred to an image support, permitting full color image formation. Thus, formation of full-color images requiring enhanced resolution, such as photographic images, has become feasible through development of image forming technologies, in addition to silver salt photography or conventional printing technology.
Images including a photographic image, such as a poster or the like, often require glossy images. When forming a photographic image by using a toner, for example, a toner image area fixed on an image support such as paper exhibits a certain extent of gloss but the white background region results in little gloss finishing. Such unbalanced finishing in gloss between an image area and a non-image area often vitiates image quality and therefore, a countermeasure has been desired.
From the foregoing background, there was studied a technique to eliminate unevenness in glossiness on the image in which image formation was performed by using a called clear toner having removed colorant components from usual toner. For instance, there was disclosed a technique in which a clear toner was supplied onto an image support having thereon a printed image and subjected to thermal fixing to form a clear toner particle layer, and thereby forming an image exhibiting uniform glossiness on the overall surface (as described in, for example, JP 11-007174 A).
There was also disclosed a technique in which a clear tone particle layer comprised of a clear toner was formed on a printed image prepared by an electrophotographic image forming apparatus, followed by formation of a clear toner layer by using a glossing device to form a glossy image (as described in, for example, JP 2002-341619 A and 2004-258537 A). In this technique, a clear toner particle layer was formed by an electrophotographic image forming apparatus and then, the clear tone particle layer surface was heated with being brought into contact with a belt of a glossing device to melt the clear toner particles and then cooled to form a glossy image.
There was also disclosed a technique of glossy image formation, in which the difference in particle size between a color toner and a clear toner was noted to achieve uniform gloss (as described in, for example, JP 2007-140037 A).
As disclosed above, a clear toner layer was formed on the image layer surface by using a clear toner, rendering it feasible to form a glossy surface with a certain extent of smoothness, whereby a glossy image was obtained.
However, it was proved that problems arose with formation of glossy images by using a clear toner disclosed in the foregoing techniques such that wrapping onto the heating roll of a heat-fixing device of an electrophotographic image forming apparatus occurred or a highly and evenly glossy image was not obtained even when using a glossing device.